Measuring current draw of a power system can be difficult due to large variances in the total electrical load. The total load of power systems vary according to the activation and deactivation of the various electrical components at any one time. For example, the load in a vehicle can vary between a few milli-amps and about one thousand amps (e.g., while starting the vehicle engine).
Typically, current measurement methods include multiple current sensors to measure the large dynamic range of current. A first sensor is calibrated to sense the current at higher ranges. A second sensor is calibrated to sense the current at lower ranges. One or more switches are controlled to activate one of the first and second sensors. Various complex switch control methods exist for activating and deactivating the sensors such that the appropriate current sensors are activated at the appropriate time. Although the complex switch control methods are minimally disruptive, providing the additional sensor can be costly.